The present invention generally concerns surgical instruments and, more particularly, pneumatically powered surgical cutting and fastening instruments. The present invention may have application in conventional endoscopic and open surgical instrumentation as well as application in robotic-assisted surgery.
Surgical cutting and fastening instruments (staplers) have been used in the prior art to simultaneously make a longitudinal incision in tissue and apply lines of staples on opposing sides of the incision. Such instruments commonly include a pair of cooperating jaw members that, if the instrument is intended for endoscopic or laparoscopic applications, are capable of passing through a cannula passageway. One of the jaw members receives a staple cartridge having at least two laterally spaced rows of staples. The other jaw member defines an anvil having staple-forming pockets aligned with the rows of staples in the cartridge. The instrument includes a plurality of reciprocating wedges which, when driven distally, pass through openings in the staple cartridge and engage drivers supporting the staples to effect the firing of the staples toward the anvil.
Over the years, a variety of different methods for actuating the cutting and staple deployment components have been developed. For example, U.S. Pat. No. 6,978,921 to Shelton, IV et al. discloses a surgical stapling instrument that employs tissue severing and staple deployment components that are driven through manual actuation of various trigger mechanisms on the handle. Other surgical stapling apparatuses have been developed that employ battery powered motors. Such a device is disclosed in U.S. Pat. No. 5,954,259 to Viola et al. Still other surgical staplers are actuated by a source of pressurized gas. For example, U.S. Pat. No. 6,619,529 to Green et al. discloses a surgical stapler that employs a source of pressurized gas in the handle that is used to power a cylinder that is also located within the handle. The cylinder houses a piston assembly that is actuated by admission of the pressurized gas into the cylinder. The piston is configured to coact with components located in the elongated tube portion and handle member to cause the deployment of the staples and the surgical knife in the distally mounted end effector. Such design, however, employs a complex collection of components for transmitting the motion of the handle-mounted piston to the components located in the end effector portion of the device. In addition, when using such a device, there is a risk that the power source becomes depleted during the surgical procedure because there is no way of monitoring the amount of gas remaining in the gas cartridge. If this occurs during the firing or retraction cycles, such devices lack means for easily exchanging the spent container with a new container or auxiliary power source.
Another pneumatically powered surgical stapling device is disclosed in US Patent Publication No. US 2006/0151567 to Roy. This device employs a pneumatically powered motor or piston system supported in the handle of the device for creating a motion that is employed to actuate the end effector. This device may be powered by removable cartridges or from an external power source, such as the hospital's existing pneumatic air or gas supply.
Such pneumatically powered devices that employ cartridges or containers in the handle portion of the device are also hampered by the size of the gas cylinder required to store the pressurized gas at sufficient volumes to facilitate actuation of the device a desired number of times at a minimum usable pressure. In the past, devices designed for large numbers of applications/procedures would either require a large cylinder to be used or, if smaller cylinders were used, such cylinders would have undesirably high pressures. In addition, devices that employ removable cartridges that can be used an unlimited number of times must be reprocessed and resterilized. Such arrangements can dramatically change performance capabilities and may therefore be less desirable.
Other problems exist with prior pneumatically actuated endocutters. For example, once the surgeon activates the instrument through a single switch or activation trigger, the instrument progresses through or at least attempts to complete the firing cycle. Thereafter, the firing components may be retracted by the drive system. While the surgeon employing the device disclosed in US Patent Publication US 2006/0151567 can interrupt the firing cycle and/or adjust the flow of gas to the device through a trigger assembly, there is no means to monitor the device's progress. In addition, such prior devices lack a means for manually retracting the knife and firing bar mechanism, should operating pressure be lost or interrupted during the procedure. Further, that device lacks a means for enabling the clinician to manually apply additional force to the drive system to assist with the advancement of the firing mechanism or to slow its advancement.
Consequently there is a need for a pneumatically powered surgical stapling device that does not require the use of an extensive collection of components to transfer the pneumatically generated stapling and firing motions to the end effector components.
There is another need for a pneumatically powered surgical stapling device that provides a means for the surgeon to control and monitor the progress of the device as it moves through the firing and retraction cycles.
There is another need for a pneumatically powered surgical stapling device that provides tactile and other feedback to the surgeon concerning the forces encountered during firing and also notification of when the device has reached its actuated position and is ready to be retracted.
There is a need for a pneumatically powered surgical stapling device that is economical and has the ability to easily interchange power sources, while limiting the number of times that such sources may be interchanged.
There is another need for methods and apparatuses for more efficiently storing gas in cylinders used to power surgical stapling devices such that more uses can be powered from a single cylinder.
There is still another need for a pneumatically powered stapling device that has means for manually retracting the knife and firing bar assembly should pneumatic power be lost or interrupted.
There is yet other need for devices with one or more of the above mentioned features and that also has an end effector that can be selectively articulated relative to the handle assembly and/or portion of the elongate shaft assembly to which it is attached.
There is still another need for devices with one or more of the above-identified features that is also capable of accommodating removably attachable end effectors to facilitate use of the device in connection with disposable end effector arrangements.